Gaya APA

Whitten, J, L, L, D, B, V, M, B. (1989). System analysis and design methods . United Stated of Amerika: Richard D. Irwin.

Gaya MLA

Whitten, Jeffrey, L.,, Lonnie, D., Bentley,, Victor, M., Barlow. "System analysis and design methods". United Stated of Amerika: Richard D. Irwin, 1989. Text.